namespace CSharpPro._1021;

public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }

    public override string ToString()
    {
        return $"Id: {Id}, Name: {Name}, Age: {Age}";
    }
}
public interface UserService
{
    // 增
    bool AddUser(User user);

    // 删
    bool DeleteUser(int userId);

    // 改
    bool UpdateUser(User user);

    // 查
    User GetUserById(int userId);
}